Dependents living abroad

Your furusato nozei limit is not a fixed number. It moves with your taxable income, and your taxable income moves with every deduction you claim, including the dependent deduction (扶養控除) for family members you support. If you claim a relative living overseas as a dependent, that deduction lowers your taxable income, which lowers your resident tax, which in turn lowers the amount you can donate through furusato nozei while still receiving a full refund through the calculator. Change who counts as a dependent, and your limit changes with it. This is especially easy to get wrong for households with relatives living outside Japan, because the rules for overseas dependents were tightened in 2023 and many people are still using the old assumptions.

The 2023 rule for overseas dependents aged 30 to 69

Since the 2023 tax year, relatives who live outside Japan (国外居住親族) are treated differently depending on their age. If the overseas relative is between 30 and 69 years old, they are excluded from the dependent deduction by default. They no longer automatically count as a dependent just because they meet the income and relationship requirements that apply domestically.

This exclusion can be lifted, but only if the relative meets at least one of three specific conditions. If none of the three apply, you cannot claim the dependent deduction for that person, even if you are genuinely supporting them financially.

Note that the remittance condition has a real threshold. Sending some money is not enough; the total sent for the year needs to reach 380,000 yen or more for that condition alone to satisfy the exclusion test.

Who is not affected

The 30-to-69 exclusion only applies to that specific age band. If your overseas dependent is under 30, or 70 and over, this rule does not touch them. They can still be claimed as a dependent under the normal rules that apply to any dependent, domestic or overseas, without needing to satisfy the student, disability, or remittance conditions. Age is calculated as of December 31 of the relevant tax year, so a dependent who turns 30 or 70 partway through the year should be checked carefully against the correct cutoff.

The documents you need

Claiming any relative living overseas as a dependent, regardless of age, requires two categories of supporting documents.

• 親族関係書類 (documents proving the family relationship), such as a copy of the relative's passport together with a copy of your family register, or a certificate issued by a foreign government confirming the relationship, name, date of birth, and address of the relative.
• 送金関係書類 (documents proving remittances), such as bank transfer records or records from services like Wise, showing money sent to that relative during the year.

For a dependent aged 30 to 69 who qualifies through the remittance condition specifically, the 送金関係書類 must show that the total sent over the year reached 380,000 yen or more. Simply having a record of some transfers is not enough; the records need to add up to that amount to support the claim. Keep these documents organized before filing, since they are what substantiates the deduction if it is ever questioned.

How this changes your limit

It helps to think through the direction of the effect rather than just the amount. A dependent deduction reduces your taxable income. Reduced taxable income means lower resident tax, and your furusato nozei limit tracks your resident tax base, so a valid dependent deduction pulls your limit down.

The 2023 rule works in reverse for many households. If an overseas relative aged 30 to 69 does not meet any of the three exceptions, you lose the deduction you may have been used to claiming in past years. Losing that deduction raises your taxable income, and a higher taxable income actually pushes your furusato nozei limit a little higher, not lower. It is a case where losing a deduction is not automatically bad news for your donation limit calculation, even though it usually does mean a higher tax bill overall.

The same logic applies to other dependent-related changes in your household, including shifts in how spouse income affects your limit, where crossing certain income thresholds changes whether a spouse deduction applies at all. Whenever your dependent situation changes, whether because a relative ages past 30, a remittance total falls short of 380,000 yen, or a document requirement is not met, it is worth recalculating your limit rather than reusing last year's figure.